1. Field
Apparatuses consistent with exemplary embodiments relate to complex spatial light modulators and three-dimensional (3D) image display apparatuses including the complex spatial light modulators.
2. Description of the Related Art
Recently, the release of three-dimensional (3D) movies is increasing, and accordingly, research into technology related to 3D image display apparatuses is increasing. A 3D image display apparatus displays a 3D image based on binocular parallax, and thus, 3D image display apparatuses that are currently commercialized use the principle of binocular parallax to allow viewers to perceive stereoscopy by respectively providing a left view image and a right view image, which differ in viewpoints, to a left eye and a right eye. Examples of the 3D image display apparatus include a glasses-type 3D image display apparatus, which requires particular glasses, and a no-glasses type 3D image display apparatus, which requires no glasses.
However, when viewing a 3D image displayed according to a binocular parallax method, eye fatigue is intense, and a 3D image display apparatus that provides only two viewpoints, that is, a left view image and a right view image, is not capable of reflecting changes in a viewpoint according to movement of the viewer, and thus it is limited in its ability to provide natural stereoscopy.
In order to display a more natural stereoscopic image, a holographic 3D image display apparatus is currently being researched. However, in order to implement a holographic 3D image display apparatus, a device that is capable of controlling not only amplitude but also phase of light is necessary. When an image is displayed by using a device that is capable of controlling only one of luminance (amplitude) and phase of light, image quality may be degraded by, for example, zero-order diffraction light, twin images, or speckles.
A holographic 3D image display apparatus may include a holographic optical element in order to control an amplitude of the light. However, such a device, for example, a Bragg grating, is composed of birefringent materials, and is therefore polarization-dependent. Thus, the use of such a holographic optical element also requires the use of a polarizer and a half-wave plate, or other polarizing optical elements in order for the amplitude of the light incident on the holographic optical element to be controlled. Such additional elements add to the complexity and cost of the device. Furthermore, the “radiation effect” problem of current holographic optical elements is known. The photopolymer function of current holographic optical elements degrades over time, causing the optical performance of the image display apparatus to decay over time. Such polarization-dependent optical elements are also expensive and difficult to manufacture and are limited in size.